Systems and methods for accurately measuring temperature perform an important function in measurements and analysis techniques used in science. Accurate measurement of temperature is often necessary in order to obtain accurate data of physical, electrical and chemical events. For instance, many chemical analyses are performed by a measurement of the time required for a chemical reaction to take place. Such time measurements have important relationships to specific measurable values characteristic of unknown components in the chemical reaction.
Generally, time dependent measurements in chemical analysis are directly related to the temperature at which the reaction takes place. The exact temperature at which a reaction occurs must be known to obtain accurate analysis results. Accurate temperature control and measurement is necessary due to the variable rates at which a reaction may progress with changes in temperature in which the reaction occurs. Increased temperatures generally increase the rate at which the chemical reaction occurs due to increased molecular activity associated with increased heat energy levels.
If time related measurements used in certain analytical procedures are to be reliable, accurate temperature control and measurement must be obtained. It is often necessary to obtain a repeatable temperature environment with accuracy to identically reproduce a selected reaction. A lack of temperature control will most certainly result in inaccuracies in any time dependent analysis.
Generally, temperature measurement and control is obtained by measurement of an element of the environment in which the chemical reaction will be, or is, taking place. For example, a measurement may be taken of the air closely surrounding the reaction vessel. More commonly, the temperature measurement is made of a structural member in which the reaction vessel is held. Theoretically, the temperature of the structural member for the reaction vessel closely approximates the temperature of the reaction vessel in which the chemicals are placed. This in turn closely approximates the temperature of the chemicals contained.
Inaccuracies are inherent in these measurement methods, however, due to differing thermal coefficients of materials, nonuniform surface contact, heat dissipation from exposed surface areas, and an inability to obtain measurement very near the point of interest, i.e. where the reaction takes place.
It is also known to make temperature measurements with a probe inserted directly into the reaction vessel and contacting the chemical in reaction. In order to prevent cross contamination between successively measured reactions, the probe must be carefully cleaned after every measurement. Furthermore, heat energy generated by the reaction may affect the measurement of steady state temperature values which must be known to control the process of the reaction.